Multipedal traction mechanism



C. E. STAHIL.

MU-LTIPEDAL TRACTION MECHANISM. 7

APPLICATION FILED OCT. 19, 1918.

1,402,16, Patented Jan. 3, 1922 4 SHEETS-SHEET 2.

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' MULTIPEDAL TRACTION MECHANISM.

APPLICATION FILED OCT-19,1918.

Patented Jan. 3, 11922.

4 SHEETS-SHEET 3- magma C. E. STAHL.

ULTIPEDAL TRACTION MECHANISM.

APPLICAHON FILED OCT. 19. 1918.

Patented Jan. 3, 1922 4 SHEETS -SHEET 4.

warren stares PATENT orrance;

CHARLES E. STAHLL, OF WINTHROP HARBOR, ILLINOIS, 'ASSIGNOR T FREDERICK AUSTIN, OF CHICAGO, ILLINOIS.

"MULTIPEDAL TRACTION MECHANISM.

aoa se.

Specification of Letters Patent.

Patented Jan. 3, 1922.

To aZZ whom it may concern):

Be it known that LCHARLEs E. STAHL, a

- citizeir o f-the United States of America, and

' tion.

a; resident? of Winthrop Harbor, .Illinois, have invented a certainnew and useful Improvement in Multipedal Traction Mecha nisrn, of which the followingis a specifica- This invention-relates to traction mechanism of that character which employs an endless belt which travels on the ground, and wheels that rest on the belt, this construction being frequently termed a multipedal tractor.

tion is to provideja novel and improved construction and arrangement of the mechanism to permita limited tilting action thereof as the belt travels over uneven ground, about a transverse axis, so: that the tractor may adjust or accommodate itself to the surfacegof the ground, and whereby the load Weight is supported onthe mechanism in away which tends to insure a strong. and substantial construction.

It is also'an objectto providecertain details and features of construction tending to increase the general efliciency and serviceability of a multi-pedal traction construction of this particular character.

To these and other useful ends the invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings- Fig. 1 is a side elevation of a multi-pedal traction mechanism embodying the princi- I ples of the invention.

' Fig. 2 is a horizontal section on line 22 in Fig. l. p

Fig. 3 is a vertical section on line 33 in Fig. 1.

Fig. 4 is a plan of two of the tractiondevices connected together by the bolster which supports the load weight, the'middle portion of said bolster being broken away for convenience of illustration.

Fig. 5 is a vertical section on line 55 in Fig. 3.

As thus illustrated, the invention comprises a pair of side members 1 which are spaced apart and rigidly connected together by a transverse beam 2 near the center, and

by top plates 3, thereby to form a. rigid frame. The load-carrying bolster comprises the transversely arranged beams 4 which enerally stated, the object of the inven-,

are spaced apart and provided at their ends with castings 5 which form the heads of the bolster. ,These castings are bored to receive the-transversely arranged driving shaft 6,

,and' the bore 7 is provided with bosses or extensions r 8 which form trunnions. The side members 1 are provided with split bearings 9 which inclose the trunnions 8, where by the latter support the load-weight imposed upon the bolster, it being understood that the latter supports the body of the ex- Icavatoror trenching machine or other body frame. I Sprocket wheels 10 and 11 are suitably-supported in bearings 12 adjustably mounted on the front and rear ends of the frame composed of the side members '1, and flanged wheels 13 are also disposed between the two side members and supported in bearings 14 thereon, these wheels 13 being substantially wider than the sprocket wheels.- A roller 15 has itsend portions or journals 16 mounted in notches 17 formed in the upstanding portions 18 on the castings 5, this construction being duplicated at opposite apart, to provide the treads for the traction belt thus formed. Relatively narrow sprocket chains 21 are spaced a distance from the sides of the sprocket belt 19, and suitably secured to the slats 20, whereby these three belts, 19, 21, and 21, are connected together by said slats.

The endof the shaft 6 is provided with a sprocket wheel 22, and the. end of the shaft 23 of the sprocket wheel 11 is provided with a sprocket wheel 24, the latter being connected by a sprocket chain 25 with said sprocket wheel 22, whereby rotation of the shaft 6 serves to drive the traction belt.

Referring to Figs. 3 and 4, it will be seen that the opposite ends of the bolster extend into the endless traction belt, and over the tilting frames of the two traction devices thus provided, so that each multi-pedal traction mechanism has a limited tilting motion about the shaft 6, the plates 3 engaging the bolster at each side of the latter to limit the tilting motion. In this way, sufficient tilting or oscillating movement is insured for'each multi pedal mechanism, while traveling overuneven surfaces, to insure proper trac tion and guard against breakage or straining of the parts, but at the same time, neither mechanism can turn clear around or tip over. The bolster communicates the e11- tire load weight'to the multi-pedal mechanism, so that no weight is imposed upon the transverse shaft 6, the trunnions 8 and their bearings 9 constituting the oscillatory or pivotal or rocking connection between the bolster and the frame of each traction device and the shaft 6 being thereby free to rotate smoothly and without any undue friction.

It will be seen that the shaft 6 forms the axle of the traction mechanism, but that with the provision of the bolster having the trunnions 8, which latter form the swivels on pivots for the mechanism, the said axle is ,what may be called a live axle, as there is no weight on it, sothat it runs freely and without undue friction, as prevlously explained. In other words, this shaft or axle 6 could be removed, and still the bolster and traction belts would support the load Weight, inasmuch as said shaft or axle serves. only to drive the mechanism, and merely servesto tilt freely up and down at the front and rear ends thereof, an endless traction belt extending around said frame and over said bolster, and means on the frame to support the load on the belt.

2. A structure as specified in claim 1, said bearings comprising trunnions on the bolster, split bearings on the frame to inclose said trunnions, a shaft in said trunnions, a

.driving connection between said shaft and the belt, means on the bolster to support the upper portlon of said belt, and means on the frame to engage the bolster and thereby.

limit the tilting motion of the frame while the belt travels over an uneven ground surface.

3. A structureas' specified in claim 1, said frame being under one end portion of the bolster, and a similarly organized frame and belt for the other end portion of the bolster.

4. In a multi-pedal traction mechanism, a truck frame, sprocket wheels on the front and rear ends of said frame, a sprocket'belt extending around said sprocket wheels, means to support the frame on the lower portion of said belt, means to imposelthe load weight on said frame, a pair of sprocket upon the top of said frame, with clearance d between the top-of the frame and the bottom p of each of said beams to permit the frame to tilt freely up and down at the front and rear ends thereof.

6. A structure as specified in claim 5, a transverse driving shaft carried by the bolster, and means whereby the frame tilts about said shaft.

. 7. In a multi-pedal traction mechanism,

the combination of an endless traction belt, a truck frame dlsposed within the belt, means on the frame to supportthe load weight on the belt, inner and outer trunnions forming aswivel connection, means between said trunnions to support the load weight thereon and thereby on said frame,

thereby to permit tilting motion of the frame and belt about a transverse axis, and ashaft' rotatable about said axis and forming a live axle free from load weight and connected tovdrive said'belt.

8. A structure as specified in claim 7 ,said trunnion forming a bearing for said shaft, and said frame having a split bearing for the trunnion. r

9. In a multi-pedal traction mechanism, the combination of a truck frame comprising inner and outer sides spaced apart, rotary members disposed between. said sides at the end of the truck frame, an endless traction belt on said members, 'means to support the truck frame on the lower portion of said belt, transverse beams spaced apart to form a load-carrying bolster which extends over said truck frame, a head secured between said beams and formed with inner and outer trunnions, and separable bearings for said trunnions on the inner-and outer sides of the truck frame, said trunnions forming an axis about which the truck frame is free to tilt while the belt is traveling formed of connected slats at each side of the over uneven ground; I I machine, means for driving said belts, means 10. A structure as specified in claim 9, including an axle extending from one trac- 15 v f said bolster extending under the upper portion device to 'the other for transmitting 5 tion of said belt, and'having means on said power to said driving means, bearings .for head to support said belt. i said axle, and tilting load-sustaining means 11. .A structure asspecified in claim 9, in comprising connected duplicated beams excombination with a drive shaft extending tending between said traction devices, and 20 through said trunnions, and a driving conmeans for imposing the load upon said bear- 10 nection from said shaft to said belt. i-ngs and relieving said axle of any of the 12. In a multi-pedal traction mechanism, Weight of said load. 2 traction devices including an endless belt CHARLES E. STAHL. v 

